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-   -   How to input transient pressure data as BC in pre? (http://www.cfd-online.com/Forums/cfx/22124-how-input-transient-pressure-data-bc-pre.html)

User February 3, 2006 03:38

How to input transient pressure data as BC in pre?
 
Hi.. I have two column of experimental data: time t & transient static pressure P(t) stored in a csv file. I wish to use P(t) as my outlet boundary condition in transient simulation.

However, I failed to initialise these data in Pre V.10.

I get an error message when I use "initialise profile data":

Invalid format .... ....unrecognised heading ....expected to read.... [spatial fields] section headings

Can anyone give me some ideas how to input the transient pressure data to Pre so that I can specify P(t) at the outlet BC.

Thank you for your help.


Camilo Costa February 3, 2006 07:42

Re: How to input transient pressure data as BC in
 
Exist in CFX help one tutorial that explain this, but i fogive was that!!

forgive my bad english!

User February 3, 2006 10:00

Re: How to input transient pressure data as BC in
 
Hi Camilo,

I found 5 (CFX 10) tutorials that talk about transient simulation.

Tutorial 4:Flow from a circular vent

Tutorial 6:Buoyant Flow in a partitioned cavity

Tutorial 12:Flow in an axial rotor/stator

Tutorial 17:Air Conditioning simulation

Tutorial 20:Fluid Structure Interaction and Mesh deformation

Tutorial 4 use formula ExpFunction to express transient term and do not use data imported from a text/csv file.

Tutorial 6 seems to use a fixed value for BC.

can't find any relavant info in Tutorial 12 as well.

Tutorial 17 uses the user subroutines ect but I can't find any methods to input t & P(t) from a csv file and use them for boundary condition.

I can't find any relavant info in Tutorial 20 either.

Did I miss out anything in tutorial? Would you mind to tell me which tutorial has the information I need? I have already spend hours to hunt for it.

Thank you very much.

Camilo Costa February 3, 2006 12:33

Re: How to input transient pressure data as BC in
 
I will sugest this!!

go in expressions anda set this example:

"2*sin((t/1[s]))[Pa] + 415[Pa]" ---> (CALL THIS VP)

clic in plot and define of 0 at 10s.

The pressure varable with time.

Go to bonduary condition that have inlet or outlet and clic in "Enter Expression" and put the name "VP"

forgive my bad english

Chirag Jayswal February 6, 2006 02:15

Re: How to input transient pressure data as BC in
 
Check following thread replying to similar query.

http://www.cfd-online.com/Forum/cfx_...cgi?read=12825

Hope this helps.

Kind regards,

Chirag


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